Bubble-free’ pumping ensures no compromise to integrity of coating film

Korea-based film coating company Anyone Tape has switched its rotary lobe pump for a MasoSine SPS 100 from Watson-Marlow Pumps Group for its adhesive-based film coating operations. Poor viscosity performance and the generation of bubbles were the primary reasons behind the change, with the SPS 100 process pump able to meet all requirements. The adhesive-based film coatings are applied to the company’s range of tapes used by blue chip customers in the electronics, telecommunications and white goods industries.

High and low viscosity

Coating film manufacturers are faced with numerous challenges when tasked with the feeding of the high viscosity adhesives. At Anyone Tape, the adhesive has a viscosity of 3000 cP, akin to honey. However, as part of a cleaning process, the pump is also required to transfer substances such as MEK (methyl ethyl ketone), a colourless organic compound, and toluene, a clear water-insoluble liquid. Added to all this, there must be no bubbles during the adhesive feeding process as these will compromise the integrity of the coating film, the face of which demands absolute uniformity.

The MasoSine SPS 100 from Watson-Marlow, which was supplied with mechanical seal and PTFE O-ring kit, provided the answer. The speed of the pump is around 50 rpm (2-3 litres/min) when feeding the adhesive, increasing to 350 rpm (18-19 litres/min) during the cleaning process comprising toluene and MEK.

The source point for the adhesive is an open storage tank, with the SPS 100 deployed to feed the substance to a discharge point on the film coating machine at a delivery pressure of 2 bar (30psi) and an accuracy of ±1.0%. Typical pump run time is 8 hours per day.

Sine pump trend

The decision by Anyone Tape to adopt MasoSine pump technology is not the first in Korea. In fact, Watson-Marlow reports that its Korean team have now supplied seven different coating film manufacturers with a total of eight sets of MasoSine SPS 100 pumps in recent months. In addition, the prognosis moving forward is for further orders.

The reason behind this trend is that MasoSine sanitary and industrial pumps are inherently designed to cater for demanding applications such as that at Anyone Tape. In fact, the range offers flows of up to 1650 litres/min 99 cubic metres/hr, pressures up to 15 bar 220psi, and viscous handling up to 8 million centipoise without modification to the pump.

Sinusoidal rotor

The MasoSine SPS 100 is ideally matched to film coating processes because its exclusive sinusoidal rotor overcomes the limitations of conventional rotary lobe pumps to produce powerful suction with low shear, low pulsation, and gentle handling, thus negating any opportunities for bubbles to occur.

Furthermore, with a single shaft and rotor, there is no need for the complex timing gears and multiple seals associated with conventional rotary lobe pumps. One rotor, one shaft and one seal equate to simple and economic maintenance.